High impact information on SKP1

• Mutations in either ASK1 or TIR1 result in decreased auxin response [1].
• SKP1/ASK1, cullin and proteasomal alpha-subunits show nuclear co-localization in differentiated Arabidopsis cells, and are observed in association with mitotic spindles and phragmoplasts during cell division [2].
• The ASK1 and ASK2 genes are essential for Arabidopsis early development [3].
• Among the 21 Arabidopsis Skp1-like genes (ASKs), it is unknown which ASK gene(s) is essential for embryo development [3].
• The F-box motif of ORE9 interacts with ASK1 (Arabidopsis Skp1-like 1), a component of the plant SCF complex [4].

Biological context of SKP1

• The yeast and human SKP1 genes regulate the mitotic cell cycle but are not yet known to be required for meiosis [5].
• Arabidopsis SKP1, a homologue of a cell cycle regulator gene, is predominantly expressed in meristematic cells [6].
• The ASK1 gene regulates B function gene expression in cooperation with UFO and LEAFY in Arabidopsis [7].
• AhSSK1, despite having a similar secondary structure to other SKP1-like proteins, appeared quite distinctive in sequence and unique in a phylogenetic analysis, in which no SSK1 ortholog could be predicted in the sequenced genomes of Arabidopsis and rice [8].
• The axr6-3 mutation interferes with Skp1 binding, thus preventing SCF complex assembly. axr6-3 displays a pleiotropic phenotype with defects in numerous SCF-regulated pathways including auxin signaling, jasmonate signaling, flower development, and photomorphogenesis [9].

Anatomical context of SKP1

• The Arabidopsis SKP1 homolog ASK1 controls meiotic chromosome remodeling and release of chromatin from the nuclear membrane and nucleolus [10].

Associations of SKP1 with chemical compounds

• The regulation of EIN3 stability by ethylene is accomplished by F-box-containing proteins that participate in the formation of a SKP1/cullin/F-box complex that targets proteins for degradation by the proteasome [11].

Physical interactions of SKP1

• EID1 interacts specifically with several Arabidopsis Skp1-like (ASK) proteins and Cullin1 to form stable dimeric and trimeric complexes [12].

Regulatory relationships of SKP1

• Furthermore, our results from RNA in situ hybridizations indicate that ASK1 regulates early AP3 and PI expression [7].

Other interactions of SKP1

• In addition, compared to the ask1 mutant, plants homozygous for ask1 and heterozygous for ask2 displayed enhanced reduction of B function, as well as other novel defects of flower development, including carpelloid sepals and an inhibition of petal development [13].
• The SKP1-Cullin/Cdc53-F-box protein ubiquitin ligases (SCF) target many important regulatory proteins for degradation and play vital roles in diverse cellular processes [14].
• Compared with the ask1 mutant, the strong ASK1 RNA interference (RNAi) line exhibited similar or enhanced phenotypes in both vegetative and floral development, whereas ASK11 RNAi plants had normal vegetative growth but mild defects in flower development [15].

Analytical, diagnostic and therapeutic context of SKP1

• Using a light squashing technique for the analysis of meiotic chromosomes along with fluorescent in situ hybridization, transmission electron microscopy and immunolocalization studies with antibodies to modified histones, we demonstrate that ASK1 is essential for early nuclear reorganization events [10].
• The interaction between AtTLP9 and ASK1 (Arabidopsis Skp1-like 1) is confirmed via yeast (Saccharomyces cerevisiae) two-hybrid assays [16].

References